1. Field of the Invention
The present invention relates to a magnetic disk apparatus having a Redundant Arrays of Independent Disks (RAID) configuration such as RAID-1 or RAID-0+1 in which the same data is written on different two disks and a control method and control program for the magnetic disk apparatus and, more particularly, to a speedup of input/output (I/O) response of the magnetic disk apparatus.
2. Description of the Related Art
Among magnetic disk apparatuses having a RAID configuration such as RAID-1 or RAID-0+1 in which the same data is written on different two disks, known is a magnetic disk apparatus that issues the same read command to respective disks when receiving a data read request from a host and adopts the data that responds first to the read command as a result of the command (refer to, for example, Jpn. Pat. Appln. Laid-Open Publication No. 4-205518).
However, different loads are applied to the respective disks, so that response to a read command may differ depending on the algorithm that executes the command in some cases. If a reading operation using a read command is performed according to a uniformly defined algorithm in the above case, the speedup of response cannot effectively be achieved.